Transmission mechanism



l R. a $ANFRD- BRANSHISSIOW mmclrmm'snu Filwd. W I- 27, 1935 s ShwW-Sheet 1 INVENTOR.

ATTORN E Y5 5 Sheets-Sheet 2 R. s. SANFORD TRANSMISSION macmmzsm Filed Sept. 27. 1935 April 151941.

INVENTOR. NFORD H 0 118% RoY 6. 5A

ATTORNEYS A an-H15, l1. s. SANFORD TRANSMISSION" MECHANISM 5 She@ts-Sheet 3 Filed Sept. '27, 1935 ATTORNEYS April 15, 1941. R. s. SANFORD TRANSMISSION MECHANISM Filed Sept. 27. 1935 5 Sheets-Sheet 4 NM NNK |||I l lll INVENTOR. ROY SANFORD ATTORNEYS 5 Sheets-Sheet 5 R. S. SANFORD TRANSMISSION MECHANISM Filed Sept. 27, 1935 April 15, 1941.-

ATTORNEYS Patented Apr. 1-941 UNITED;

TRANSMISSION MECHANISM Roy S. Sanford, New York, N. Y., asslgnor to Bendix Products Corporation, South Bend; Ind., a corporation of Indiana Application September 2'1, 1935, SerialNo. 42,419

5 Claims.

'My invention relates to vehicle control mechanism and has particular reference to automatically operable change-speed mechanism, substantially eliminatingthe necessity of manual effort on the part of the vehicle driver.

An object of the invention is to utilize powe derived from the internal-combustion engine of a motor vehicle for actuating the customary transmission mechanism ordinarily manipulated by hand through a gear shift lever. More particularly, I contemplate utilizing the vacuum produced by said engine for this purpose.

A further object of the invention is to utilize the same power source for the purpose of automatically throwing out the clutch between the engine and the drive shaft in proper timedrelation to the gear shifting operation. An important feature of the invention resides in the control mechanism and the manner in which the various elements thereof are associated, whereby the declutching and gear shifting operations are automatically accomplished in :proper timed relation to the releasing and depressing operations of the accelerator pedal, which controls the fuel supply. By virtue of this particular association v of control units and the timed relation therebetween it is unnecessary for the driver of the vehicle 'to learn anything new for the purpose of properly operating the, same. The operations specified takeplace automatically when the drlver manipulates the accelerator pedal in the manner in whichhe isjalready accustomed in conjunction with the ordinary manually operable control units.

An importantfeature of the invention resides in the arrangementwherebycomplete declutchmg is insured prior toautomatic operation of the transmission mechanism, thereby eliminating the possibility of clash or stripping of the gears. $1- other feature, of importance resides .in the particular valve controlutilized whereby sumcient vacuum power from the gcombustion engine to perform the aforesaid operations is assured with or without utilizing an auxiliary vacuum tank as an added source of vacuum supply. The rise a fall of the vacuum power available from the in.- take manifold of the combustion engine in accordance with the load of the cosine is well known. My improvedvalve control arrangement insures the building up of sufllcientvacuum in the operating lines to completely perform all of the aforesaid operations, regardless of any momentary drop in the vacuum available from the intake source.

. is desired.

rate manually operablecontrol mechanism, easily accessible to the driver of the vehicle, for adjusting the vacuum power line in such manner that the transmission will automatically be thrown in reverse gear upon depression of the accelerator pedal, when such backward movement An important feature resides in the control means whereby the transmission gears may be maintained in neutral position, when the driver desires to race the motor for warming up the engine, et cetera.

Still another object of the invention resides in the manner in which the vacuum power lines are automatically controlled to insure complete shifting of the transmission gears prior to re-engagement of the clutch for driving purposes.

Still, a further feature of importance resides in the association of a free-wheeling unit with the transmission mechanism and the provision of means automatically operable, when such freewheeling mechanism is in the locked-out position,

to throw the said unit into free-wheeling during the. period of, gear shifting. Since the clutch providing a drive engagement between the engine and the drive shaft is positioned forwardly of the transmission and since the free-wheeling unit is positioned rearwardly thereof, simultaneous dc clutching and operation of the free-wheeling unit will unload both ends of the transmission so that gear shifting may be accomplished without clash. An important feature also resides in the arrangement whereby the vacuum'power may be utilized to control the position of the free-wheeling unit. The means for determining the position at which such free-wheeling unit is to be normally retained may be located conveniently upon the dash panel.

Various other objects and meritorious features of the invention will be apparent from the following description taken in conjunction with the drawings, wherein like numerals refer to like parts throughout the several figures and wherein:

Figure 1 is a side elevation of the assembled mechanism, somewhat diagrammatic for illustrainder controlling second and third speeds:

Figure 5 is a' section through the clutch operat- A further object of the invention is to incorpomg power cylinder;

Figure 6 is a section through the speed controlled gear shift valve, the part. thereof being illustrated in first speed position;

Figure '7 illustrates the same valve in second speed position; I

Figure 8 illustrates the valve in third speed position;

Figure 9 is a sectionthrough what may be regarded as. the primary and secondary control valves;

Figure 10 is a section through the dash positioned reverse and neutral valve adjustment;

Figure 11 is a section through the primary control valve illustrated in section in Figure 9, said valve being in the position occupied just prior to closing the vacuum lines;

Figure 12 illustrates diagrammatically a control system similar, but slightly modified as to detail, to that illustrated in Figure 1, wherein a free-wheeling control is incorporated;

Figure 13 is a section through the one-way valve with the auxiliary vacuum tank forming a part of the system in Figure 12; and

Figure 14 is a section through the air valve in the power cylinder mechanism shown in Figure 12.

Referring now to the diagrammatic illustration of Figure ,1, numeral I represents an intake manifold associated in conventional manner with the engine of a vehicle. A carburetor I2 is associated therewith, said carburetor being manipulated from the hand throttle by a rod I4 through a lost motion connection I6 and operable by an accelerator I8 through rod 20 and lost motion connection 22. A spring 24 is positioned in conventional manner to normally urge the butterfly valve of the carburetor into motor idling position. Both the hand throttle which is usually mounted on the dash and thefoot operated accelerator may be defined as fuel control elements.

Fixedly positioned by the accelerator rod 20 is a bracket 26 to which is secured one end of a spring 28, the other end of said spring being secured to some fixed portion of the vehicle as indicated at 30. The bracket includes a depending arm 32 apertured at its extremity to permit valve rod 34 to slide therethrough. Said rodis provided at its extremity with an enlarged head 38, whereby the forward movement of the rod is limited by the position of the bracket 26. .It will be apparent therefore that depression of the accontrol valve 40. In its retractedfor rearward.

position, as illustrated in Figures '1 and 9, the valve 40 opens the vacuum line 42 extending from the intake manifold to communication with vacuum line 44 extending to the clutch operating power cylinder 46. From the clutch booster cylinder a vacuum line 4l communicates through a three-way fitting 50 with line 52', one end of which communicates with a manually operated secondary control valve 54 and the other end of which communicates with a portion of a gov-' ernor controlled valve 56. The valve 64 constitutes a selector means and the valve 50 a speed responsive means for in large measure controlling the operation of the transmissionoperating mechanism. The secondarycontrol valve 54 or selector communicates, through lines 58 and 60 with a power cylinder 62 and the speed controlled valve 56 respectively. Communicating passages 64 and 68 extend from the valve 58 to opposite ends of the booster cylinder 68 and another vacuum line 10 extends from the said valve to the end of booster cylinder 62 opposite to that into which line 58 opens. ConduitfiZ provides communication between the central portion of power cylinder 68 and the valve 56 for purposes of venting the central portion of said cylinder to air in a manner clearly described hereinafter. Power cylinders 62 and 68 are provided with piston actuated stems I4 and I6 respectively which operate shifting forks l8 and 00 to shift gears within the transmission 8! in the same manner as such shifting forks operate in a conventional lever actuated structure.

As hitherto stated, Figures 1 and 9 illustrate the primary control valve 40 in position 'to establish'communication between the intake manifold and the clutch operating power cylinder 46. The vacuum created by the motor draws the piston 02 forwardly in the cylinder 46, thereby throwing out the clutch through the connection 8% between the piston stem 86 and the clutch actuating lever 88.

Power cylinder 46 comprises a cylinder casing, the open ends of which are closed respectively by integral threaded heads 90 and 92. The head 92 includes a one-way valve 95 operable against the coil spring 96 to admit air to the cylinder when the piston 82 is moving in clutch release direction. The rear end of the power cylinder 46 is vented to air at all times through the adjustable vent S8. Piston stem 86 is provided with a slot I00 extending from the rear extremity thereof to a point somewhere near the piston 82 for purposes to be described more fully hereinafter.

The closure head 90 is fixedly positioned with relation to the chassis, as by means of some fixed element I02, and includes a communicating passage I04 which is normally closed by a valve I06. Passage I04 communicates with a line 48 extend- 82 has reached substantially the limit of'its -movement in clutch release direction. It will therefore be apparent that line 48 is not opened to vacuum until the clutch between the engine and the transmission has been completely released.

Assuming that the vehicle is standing still,

with the accelerator raised as indicated in the drawings, the valve I08 of the speed controlled valve 56 will be in the position illustrated in Figure 6 This valve is actuated against the resistance of a coil spring IIII'by any desirable type of neutral. and the vehicle standing still. Under such conditions the accelerator pedal will be in its fully released position, as illustrated in Figure 1"- 1. thereby retaining the spool valve 30 of primary control valve 40 in the position illustrated in Figure 9. It will be noted that the primary control valve 40 includes a by-pass I I6, which conpower which must be built up in the forward end. of primary control valve 46, and simultaneously in the vacuum lines through conduit 44, before the spool valve 38 continues its forward movement to shut off the vacuum lines from the vacuum source.

The car is now moving forwardlyin first speed. and when the operator is ready to shift into second the normal action is to release the accelerator pedal. Shifting into second occurs automatically upon such release in the manner hereinafter described. The vacuum lines are again opened by rearward movement of spool valve 38 through the one-way connection of the bracket 26 with thevalve stem 34. Spool valve H8 is again positioned as illustrated in Figure 9 as the head I36 abuts head 36. The clutch is thrown out initially upon operation of the piston 'inbooster cylinder 46 prior to opening the line 52. At this point the vehicle has gained suflicient speed to draw the valve I68 in the speed controlled valve 56 to the position illustrated in Figure '7. In this position, the forward end of the gear shift booster 62 has been vented to air through a slot I64 in the valve I68, access to the atmosphere being had through a vent I66 in the forward end of the speed controlled valve 56. reverse speed gears are disengaged. Simultaneously, communication is established with the right-hand end of cylinder 68 through the line 52 which opens into port I68, which port registers with slot I26 in valve I68 leading to the annular space provided by the restricted neck I22. Communication is thus established with the port I16 and the vacuum operates through line 66 connected with said port to the rear end of cylinder 66. At this point the central part of said cylinder 66 is vented to the air through line I2, which line is opened to the atmospherethrough a transverse passage I12 in the valve I68, said transverse passageway connecting with an axial bore II4 extending forwardly through .said valve to the atmospheric pressure established in the forward end of the valve through the vent I66. The piston I26 in gear shift cylinder 66 is therefore urged against the stop member I'I6 to actuate the shifting fork 66 to throw the transmission gears into second speed. The speed controlled valve I66 prevents slipping back into first gear when the accelerator is released momentarily. The vehicle may be driven at as high speed as desired in second so long as the accelerator is not released in the third speed range.

Subsequent movement of the accelerator pedal I6 will close the'vacuum line by operation of the primary control valve 46 as hitherto explained.

When suflicient speed has been attained to warrant shifting into third, the accelerator pedal is again relieved, whereupon the vacuum lines are opened, the clutch motor 46 operates to throw the clutch out, and the following action takes place by reason of the changed position of valve I66 in reason of the fact that the port I16 is open to the annular space provided by the restricted neck I22 of the said valve I66. At the same time cylinder 66 between pistons'i24 and I26 is vented Therefore, first and v to-air by registration of the transverse passage I66 in the valve I68 with the line I2. Simultaneously, air is admitted to cylinder 68 on the right-hand side of piston I26 by reason of the registration of transverse passageway I12 with theport I16. It will be apparent therefore that the suction on the left side of piston I24 draws the piston leftwardly in the cylinder and by reason of its contact with the stop member I82 draws the rod I6 along with the shifting fork 86 to shift the transmission gears from second to third speeds. Upon depression of the accelerator pedal the line 44 will be closed to vacuum and open to air as soon as the primary control valve 46 operates, as previously explained.

It will be seen that during movement of the vehicle the accelerator pedal may be manipulated as desired without any particular care on the part of the operator, because the position of the speed controlled valve 56 determines the particular gear in which the transmission operates. If the accelerator pedal is released while the vehicle is in third speed and the speed drops to the second speed range, the second speed vacuum line 66 will be opened and the transmission will automatically be placed in second speed. If the accelerator pedal is left in released position and the speed of the vehicle drops to first speed range, the vacuum line I2 will be opened and the transmission is thrown into neutral. The secondary control valve H8 cuts off the first speed line 66 from communication with vacuum source. For this reason the vehicle can never be in gear when standing still.

By reason of slot I66 in the piston stem 86 associated with the clutch operating power cylinder air is permitted to escape rapidly from the rear end of said cylinder during initial movement of the piston in clutch release direction. However, as the end of the cylinder is approached, the slot outlet will be closed and the remaining air trapped in the cylinder can escape only through the adjustable valve 98. In this way a cushion effect is secured during the final movement of the piston and an easy reengagement or engagement of the clutch is assured.

Another important feature inherent in the control mechanism hitherto described resides in the fact that the piston 82 of the clutch control motor can not move rearwardly sufliciently far to permit reengagement of the clutch until the gear shifting operation is completed. The reason for this is that the vacuum operating through the lines to any one of the gear shift motors must necessarily have become sufficiently powerful to perform the gear shifting operation before the primary control valve 46 closes the lines from the vacuum source, as hitherto explained. This is true by reason of the momentary check acting on valve 38 through the spring pressed balls The second and third speed transmission gears herein, since "the means utilized has nothing,

whatever to do-with the particular invention here involved.

' positioned as at I92 to a bracket I94 projecting away from the housing I66 of the mechanism. The other extremity of the rocker arm is provided with a slot I98 engageable with a pin 266 positioned at one extremity of a shaft ltd extending into the housing ltf. A shaft can is rotated through engagement of pinion 205 with a part rotated by the drive shaft ,of the vehicle, to which these arms. are weighted as indicated at fill.

and the pivotal ends thereof include teethtft adapted to mesh with a rack portion tit provided adjacent the upper extremity of the shaft fill.

it will therefore be apparent that as the shaft tilt is rotated, the'sleeve ill will rotate therewith and the arms fit and tit will he moved outwardly by the centrifugal force developed. lhis action will cause sliding movement of the shaft rat and consequent rocmng overnent of the roclrer arm use about its pivotal point to actuate the shaft ilf which, in turn, actuates the speed controlled valve lit. 7

Means have also been provided operable from the dash of the vehicle, or from any other convenlent position, to control the vacuum lines for permitting shifting into reverse automatically or to permit racing of the motor without shifting into any gear. This means has been illustrated more clearly in Figures 9 and 10. The rear end of spool valve lid of secondary control valve '54 is closed by a threaded closure fill, the interior of said valve being provided with a bore fit, which is extended rearwardly throughout the length of the spool valve through a smaller bore tit pro vided in the said closure member. One end of a cable flit, adapted to'slidewlthin a conduit tilt, entends into the bore tit and is provided with an enlarged head ti t adapted to slide therein lie-- tween the forward limit of the bore and the reto this plunger, the cylindrical surface of whichis provided with a plurality of annular grooves ltd, tar, and fit in which a spring pressed ball ltd is adapted to seat.

l 'igurw ill-"and lil illustrate the parts hitherto described in position to permit shifting to all forward speeds. en the member 2ft is drawn rearwardly so that the ball 258 engages the annular groove-r52, the head 2% at the opposite end of the cable 2% will have been drawn rearwardly to a point at which it abuts the closure 224 pro vided for the rear' end on. the spool valve H8.

Under'these circumstances it will be apparent that the said spool valve lldcannot move forwardly when the abutting head 38 is removed to permit sliding movement 01' valve rod I3 2. As hitherto explained, such sliding movement of the valve rod and spool valve sin aforwardly direction occurs prior to opening the vacuum lines to permit shifting into first gear. Since the spool valve is positively held against such movement by the I cable 230, the accelerator may be depressed spasmedically as much as desired without opening the vacuum lines for shifting into first. This particular adjustmentis necessary to permit rac- 75 ing the motor for warming up purposes, et cetera.

"When member 245 of the dash control is pulled further 'rearwardly, the spring pressed ball 258 will engage annular groove 250 to retain it in its rearmost position. In this P sition the spool valve i it will have been drawn rearwardly against the resistance of spring ltf, thereby opening the port ltd for communication with the vacuum line if and closing the same to the air vents ltd. This permits operation of the vacuum through the line it, which extends to the rear end of gear shift motor t2, thereby cooperating with the air vent idt in said motor to force the piston I to the right against the resistance of spring I54 to actuate the shifting fork It to throw the transa mission into reverse gear. The operation of the clutch motor it during reverse shifting of the transmission gears is exactly the same as explained in. conjunction with shifting in the forward speeds.

A somewhat modified control assembly has been illustrated diagran'imatically in Figure 12. In this system a free wheeling' unit tfif is shown mounted on the rear of the transmission ii. A lever f-t i is operable to throw the free-wheeling unit into free-wheeling or locked-out positionin a mannerand for that reason an auxiliary vacuum tank fit is connected with the intake manifold it through the conduit tit and the one-way valve f'll illustrated in Figure 13. This valve includes a spring pressed plunger t'lt provided with open- I ings tut adapted to register with vacuum passages iltf when the plunger is in its forward position as illustrated in Figure 13. The rear extremity of the valve casing is vented to air through the passages fit and its, whereby the plunger are is forced into the position illustrated in Figure 13 when vacuum from the intake manifold has reached the interior of the valve on the other side of the said plunger 218. When the vacuum in line fit is insuiiicient to overcome the resistance of the spring 288, then port 282 will he closed,

thereby preventing any decrease in the vacuum already attained in tank 214.

The vacuum conduit 42" extending from tank tit to primary control valve 40' is the same in a functional way as line 42 oi the system illustrated in Figure l, and the remainder of .the

gear shifting system and vacuumv line control relating thereto is precisely the'same as that already described. However, a line 290 extends from tank 2M toport 292 in free-wheelingcon- 'trol valve 29d. "Another line 29.6 extends from anotherport 298- in said control valve tofitting 50', which latter differs from the fitting 50 illustrated in Figure 1 only in that it is a"four-way connection rather than a three-way aflair. The

control valve 294 is provided with a third port manipulated through control arm 30G positioned on the dash, or any other desirable member, and

connected in suitable fashion, as through link shift 'gears. celerator pedal .will not be fully released and will through line 296 after passing into the clutch control motor 46 to operate the free-wheeling control booster 268. In this way both ends of the transmission 8I will be unloaded during the gear shifting manipulation, which avoids any I possibility of clash and insures silent, rapid operation of the transmission.

The free-wheeling control motor 268 is provided with an adjustable air vent illustrated in Figure 14. The vents 3I2 and 3I6 are normally closed on the inside by a valve head 3I8 positioned on the inner extremity of valve stem 320. The valve stem is slidable through the end of the motor cylinder and includes a bore 322 into which an adjusting needle 324 is threaded. A washer 326 provides a seat for one extremity of coil spring 328, the other end of which is seated upon the exterior of the motor cylinder casing, thereby normally urging the Valve 3I8 to close the ports 3l2 and 3I6. Aboss 338, through which the valve stem 328 extends, is radially apertured as indicated at 332, these apertures registering with corresponding apertures in the valve stem 320 when'the valve ports are in the positsion illustrated in Figure 14, the large ports 3l2 and 3I6 being closed. The bore 322 is provided with access to the interior of the cylinder through a restricted passage 334.

Thus it will be apparent. that valve 3I8 will unseat to admit a rush of air when the opposite end of the motor 268 is opened to vacuum to draw the piston 210 forwardly. On the other hand, ports 3I2 and 3I6 will be closed on movement of the piston 210 in the reverse direction, and the exhaust of air will take place through the restricted passage 334 and the registering apertures in the valve stem and the boss 330. The speed of this exhaust may be controlled by adjusting the needle 324 in the valve stem 320 so that the forward unit will not move to locked-out position until the motor speed has reached the vehicle speed and the unit has engaged in the forward position.

A further description of the operation of the device under varying circumstances will render the utility of the structure more apparent. When the accelerator pedal is depressed by the operator, the transmission mechanism being in third speed as under normal driving conditions, it may be desirable to gradually lift the said accelerator untilthe speed of the vehicle is very low, say three'or four miles per hour without desiring to Under such circumstances the acmary control valve 38 -to exhaust air from the clutch operating power cylinder. At this point the valve stem 34 will center the secondary valve II8 which, as hitherto stated, cuts oil Vac communication with the vacuum lines extending to the first speed transmission piston I42. At the same time the speed controlled valve I08 permits the exhaust of air through vacuum lines 52 and I2 from the right side of the piston I24, the left side of which will be vented to air through the vents 586 in the speed controlled valve-casing. This disengages the transmission gears from their third speed relation. At the same time the righthand side of the second and third speed motor cylinder 68 will also be vented to air through line 66, thereby permitting the exhaust of .air through I2 to center the two pistons I24 and I26 in the cylinder 68. In this position the transmission assembly is in a neutral position.

Where the accelerator pedal is released in third speed and the-car-is permitted to coast, there will be an immediate de-clutching I through the clutch booster and a shifting from third to second speed as the speed controlled valve I08 is actuated by the decreasing speed of the vehicle. Since the vacuum line 60 is cut off from the vacuum source by the secondary control valve II8 when the accelerator is re-- It will be further apparent that there can be no shifting of the transmission mechanism without complete release of the accelerator, the release being at least sufiicient to bring into ef feet the lost motion connection 22 with the carburetor. Furthermore, this release which positively actuates the valve 38 to establish commine the operation of said transmission operating munication between'the vacuum source and the other vacuum lines need only be momentary to effect the de-clutching and shifting action. This is because subsequent depression of the accelerator after such momentary release does not positively actuate the primaryvalve 38, which valve remains in open position until'the various lines have been exhausted and the secondary valves'have shifted to thereby vent the central portion of valve 38 to air. At this point the valve 38 is drawn forwardly by the Suction established in the forward part of the primary control valve through the passage II6.

It will be seen that the shifting of the gears will take place automatically immediately following a momentary release and subsequent depression of the accelerator pedal. This is secured by the selecting function of the speed controlled valve I08, which becomes operative once communication with the vacuum source has been established by the primary valve.

I claim:

1. In an automotive vehicle including an engine intake manifold, a clutch, transmission mechanism, and a free-wheeling unit, means operable by the vacuum in said manifold to successively throw out said clutch, throw said freewheeling unit from locked-out to free-wheeling position, and actuate the gears of said transmission, said means including a plurality of pressure differential operated motors, and further including a valve mechanism automatically operable in accordance with the speed of the vehicle to deter-' mechanism.

2. In an automotive vehicle provided with a clutch, a transmission, a throttle, and a throttle operating accelerator, power means for operating an intake manifold, a throttle, an accelerator for controlling the operation of said throttle, transmission mechanism and a clutch, means including a clutch operating pressure differential oper ated motor and a transmission operating pressure diifer'entlal operated motor both of said motors being rendered operative by means controlled by said accelerator and being operative to successively declutch the engine and shift the transmission gears, said declutching means including a valve mechanism operable by the power element of the clutch operating motor, said valve mechanism being operable to insure declutching prior to gearshiiting and operable in the reverse manner to insure gearshifting prior to re-engagement of the clutch.

i. 'llhe combination of an internal combustion engine, a vacuum operated clutch operating mechanism comprising a single acting pressure diflerential operated motor, a .vacuum operated gearshift, a fuel control element. means whereby the operation of the clutch is dependent upon the position of the fuel control element, and means mounted on the suction side of said motor and operated by the power element thereof to make the vacuum available to the gearshift when the clutch is in a predetermined position. 5. 'I'he combination with a source of vacuum, fuel control element, a change-speed transmission and a clutch, of a vacuum operated clutch operating mechanism comprising a pressure differential operated motor including a piston, a valve operatively connected with the fuel control element for in part controlling the operation of said motor, a vacuum mechanism comprising a pressure differential operated motor and means for controlling the operation oi the transmission operating mechanism comprising means operated by the piston of the clutch operating pressure differential operated motor and mounted on the cylinder of said motor, a manually operated selector means, a

and further comprising a governor operated means, said aforementioned mechanism'being so constructed and arranged as to eii'ect a disen. Easement of the clutch when the fuel control elementds moved to its engine idling position and no? 3. SANFORD.

operated transmission operating 

